Without limiting the scope of the invention, its background is described in connection with calcium supplements and dietary supplementation. Two patents (U.S. Pat. Nos. 5,432,200 & 5,219,889), in which the inventor of this patent served as a co-inventor, are patents that teach methods for manufacture of calcium supplements. While one of these patents teaches a composition that may include KMgCitrate as a dietary supplement of potassium and magnesium specific mentions to disease conditions is lacking. A follow-up patent (U.S. Pat. No. 7,091,246 B2) offered improved process of making KMgCitrate, again with only reference to general dietary supplementation.
PCT/SE89/00410 and PCT/EP94/03072 advocated a palatable salt substitute to be added to food, instead of a tablet pharmaceutical formulation as with KMgCitrate. The active ingredient is entirely different from KMgCitrate; it is composed of “carnallite” and “kainite,” which are chloride and/or sulfate salts of potassium and magnesium without any citrate. Unlike KMgCitrate, these “double salts” do not confer an alkali load; thus, they neither correct the metabolic disturbances of undue urinary acidity of gouty diathesis nor possess antihypertensive action of alkali discussed above. The blood pressure lowering effect of these salt substitutes may be ascribed to the reduced intake of sodium (from the substitution of table salt) and other additives whose purpose or actions are poorly described.
US 2004/0224076 A1 recommended a salt substitute rather than a pharmaceutical preparation as with KMgCitrate. Rather than a single compound, it is a mixture, which contains additional substances not present in KMgCitrate (sodium, chloride, and calcium). Its principal component is potassium salt of chloride rather than citrate. Thus, it is devoid of desirable alkalinizing action. Hypotensive effect of such salt substitute, inferred but not directly tested, can be explained by reduced intake of substituted salt.
U.S. Pat. No. 6,136,349 teaches a method of making food seasoning or food ingredient, by adding mixtures of salts as well as plant sterols and/or stanols. The mixture contains calcium (absent in KMgCitrate), and has potassium and magnesium as non-citrate salts. The claims of this invention may be applicable to experimental rats, but not necessarily to human beings.
US 2005/0123670 A1 is a liquid preparation to be used as a seasoning, rather than a tablet formulation. Unlike KMgCitrate, it contains calcium and incorporates potassium chloride rather than potassium citrate. No mention was made of its use in the management of hypertension.
PCT/US2004/006349 is a method for making a food seasoning of agreeable taste, rather than a tablet formulation as with KMgCitrate. It contains a mixture of salts, including a calcium salt and sodium chloride, which are absent in KMgCitrate. Magnesium is present as magnesium sulfate, an insoluble salt of poor bioavailability. It describes the process of making but does not mention use in hypertension.
U.S. Pat. No. 6,881,750 B2 is a composition comprising potassium taurate bicarbonate and/or potassium taurate ascorbate—substances that are entirely different than KMgCitrate. It was tested in experimental rats given a high salt diet, not in human beings.
JP1300874 is a method for “nourishing” food items such as soybean or gluten by adding various salts. Calcium is added as a bone meal, a poorly soluble calcium phosphate. JP6343417 includes a salt seasoning that contains sodium, calcium, potassium and magnesium as chloride salts. Thus, they differ from KMgCitrate, a citrate salt of potassium and magnesium to be used as a tablet pharmaceutical preparation.
CN1090483C is features a method for making a tablet preparation containing potassium and magnesium. However, it is clearly not the same as KMgCitrate of the present invention. Potassium is present as a chloride salt, which does not confer an alkali load and which is believed to be not as effective as potassium alkali in controlling high blood pressure (Morris et al., Semin Nephrol 19: 487-493, 1999). It incorporates magnesium as a chloride or sulfate salt. While magnesium chloride is soluble, it confers an acid load (rather than an alkali load provided by KMgCitrate); acid load can cause bone loss, low urinary citrate and propensity for stone formation. Magnesium sulfate is poorly soluble and sparingly bioavailable. Three case reports are presented to support the claim in hypertension. However, none of the cases can be professed to be convincing.